Pressure cap



March 26, c, 8, Emmy 2,195,266

PRESSURE GAP Filed Feb. 24 1939 3npentor (we; 61 fiaz'lq A attorneys Patented Mar. 26,1940

.- UNITED STATES j PATENT; ori-"ice v Charles S. Bailey; Lockport, N. L, assignmto General Motors Corporation, Detroit, Mich., a corporation of Delaware Application February 24, 1939, Serial No. 258,120 1 5 Claims.' (01.220-44) vide a device for better control of internal system pump l which draws water or other cooling liquid pressure.

Additional objects will become apparent from the following detail description when taken with the accompanying drawing wherein Figure 1,is a fragmentary view illustrating a conventional engine cooling system; Figure 2 is a section of the filler spout taken on line 2-2 of Figure 1'; Figure 3 is an enlarged detail sectional view'of the filler spout and cap assembly and is taken on line 3-3 of Figure 2 and Figure 4 is-aperspective view of the vacuum relief valve.

For cooling the engine of an automobile the customary practice is to provide an engine driven through a hose 2 from the bottom tank or header 3 of ,the radiator core 4 and forces the water through the cooling jacket of the engine 5 and back to the radiator core 4 through the hose connection 6 and radiator top tank I. Heat absorbed in the-water jacket of the engine is transferred to an air stream drawn through the radiator .4 by an engine driven fan 8. The system is v filled with cooling water by means of a spout 9 having at its inner end an internal pflange l soldered or otherwise secured in a depressed seat II at the rim of an opening in the top tank I. The spout is vented through an overflow pipe l2 leading laterally therefrom and downwardly beside the radiator for discharge'near thebottom thereof. The spout is shown as having the usual by the annular flange l3 and provide .at their- .lower edges a pair of camming abutments constituting a part of a bayonet connection for a removable filler cap.

For closing the overflow vent I2 from the cooling system there may besubstituted for the usual spout closure cap, an assembly which includes a pressure relief valve carried by a cap to extend into the spout for seating engagement on the internal spout flange I0. In the structure illus-,-

, 'trated, the cap 16 has a pair of inturned tongues I! struck from the skirt of the cap for sliding engagement with the cam edges of the dependent spout portions I for detachably securingthe cap to the spout. A spring diaphragm I! of hard brass is secured either fixedly or rotatably according to choice, on the underside of the cap, by having its inner edge reversely bent as at 19 about the rim of an opening in a central depres- 5 sion 20 of the cap. At its periphery the diaphragm I8 is provided with circular corrugations for increasing the flexibility thereof and one of these corrugations is engageable with the'annular ridge 14 on the spout toefiect a seal at the outer end of the spout. The arrangement of the parts is such that in the applied position the spring diaphragm is stressed and maintains aseal by. reason of its natural elasticity.

Soldered or otherwise secured on the underside ll of the diaphragm i8 is an endmost'disc of a hollow flexible bellows 2|, the opposite endmost disc of which has secured thereon a stamped metal plate 22' whose peripheral edge is adapted to engage a gasket '23 resting onfthe inturned flange |0.' Displacement of the gasket 23 is prevented by indentations 24 formed in the wall of the spout 9." Centrally of the plate 22 is an apertured domeportion' 25 extending into the lower. end of the hollow bellows 2| and having three or more circumferentially spaced raised pimples or tits 26 for supporting inspa'ced relation with the dome 25 a buoyant valve 21. The float valve 21 is in the nature of a hollow thin walled stamping havinga series of circumferentially spaced and radially projecting guide ribs 28 which may have sliding contact with the inner edges of the bellows discs to maintain the valve at an upright position. The bottom wall of the valve consists 01' a disc 29 having outwardly extending ears 30 fitting the'bottom of the several ribs 28 together with upstanding attachment flanges 3| which are soldered or otherwise secured to th wall of the cupped stamping 2'! constituting the main body of the valve. The upper end or nose 32 of the valve body is of conical shape sothat it is selfcentering on its seat at the vent opening through the cap it. This valve seat is shownas consisting of an annular ring 33 of elastic deformable material such as rubber or neoprene with a peripheral groove to fit the rim of the opening through the cap. Its deformable character assists in providing a tight seal when the valve is buoyed upwardly into engagement therewith.

Upon the application of the cap to the filler 50 spout the position of the parts will be that shown in Figure 3. In this position while the usual overflow vent pipe I2 will be cut ofl from the system by reason of the spring bellows 2| seatopen to atmosphere around the valve 21 and interior of the bellows 2i. This venting enables any air entrapped in the coolingsolution to escape and remains open until such system temperature is reached that either expanded liquid or presure vapor buoys the valve 2'! upwardly against the grommet 33.

As the liquid in the cooling system takes on heat it also expands in volume. If the liquid level rises into the bellows the float valve 2! will be lifted until it is seated over the opening in the cap 86 and any further expansion taking place will build up an internal pressure which raises the boiling point of the liquid and enables it better toabsorb and transfer heat. However, should the pressure exceed the predetermined value of the spring bellows M the pressure relief valve 22 will be unseated for the relief of pressure through the overflow it until the pressure drop again permits the valve 22 to be seated.

More particularly the expansion within the system takes place as a result of the formationof steam and the formation of steam is most likely to occur as a result of what is termed after boiling. The presence of vapors under pressure in the system will buoy up the valve 21' into 1 seating position and at the predetermined pressure the pressure relief valve is lifted for a balcap having a valve seat surrounding an aperture therethrough, a pressure relief valve spaced inwardly of the cap and adapted to seat on the inner end of the spout, a spring hollow bellows con-.

nected at one end to the cap beyond the rim of said valve seat and connected at the other end to the valve to seal the space between the valve and cap and a gravity opened vent valvecontained within and guided by the bellows for engagement with the valve seat at the aperture in the cap.

2. For association with a detachable spout closure cap having a dependent hollow, spring bel-- lows for seating a pressure relief valve, a ring of elastic deformable material afiording a valve seat at aflvent opening in the cap and a floating valve contained within and guided by the bellows to seat on said ring for cooperation with the first mentioned valve in completing the spout closure.

3. In a valving organisation tor a vented filler spout having a valve seat at its inner end and a cap engaging part at its outer end, a cap detachably engageable with the outer end of the spout, a pressure relief valve engageable with said seat to close the inner end of the spout irom the spout vent, a hollow spring bellows having its opposite ends secured to the cap and valve, respectively, and serving to seat the valve, and a gravity opened valve enclosed within and guided by the bellows and adapted to be buoyed. upwardly to close a vent opening in the cap to condition operation of the bellows seated valve;

4:. A valve unit for a filler spout, including a cap having a vent opening therein, a hollow bellows secured on the undersideof the cap.

around said opening, a buoyant vent valve enclosed and guided by the bellows to seat over the opening, a spout engaging pressure relief 5. Control valving for} a pressure system, in-

cludlng a member having a vent port therethrough, a hollow spring bellows secured at one end on the undersideof the member beyondthe rim of said port, a pressure actuated valve car-- rled on theother end of said spring bellows and adapted to be yleldably seatedthereby and a buoyant valve housed within and guided by the bellows to and from it's seat over the vent port .tor action in conjunction with the pressure actuated valve in the controloi. system pressure. CHARLES S. BAILEY. 

